Two New Mutations in dnaJ suppress DNA damage hypersensitivity and capsule overproduction phenotypes of Δlon Mutant of Escherichia coli by Modulating the Expression of ClpYQ (hslVU) and rcsA genes.

•H33Y (flm-1) and P34S (flm-2) mutations in dnaJ were isolated as new suppressors of Δlon mutation.•Both mutations affect HPD motif and suppress Δlon phenotypes to different extents.•Loss of trans-translation coupled with flm mutations leads to stronger suppression.•Upregulation of ClpYQ protease leads to suppression of DNA damage sensitive phenotype.•Downregulation of rcsA leads to reduced capsule synthesis in Δlon dnaJ mutants.